ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

4pSC6. Animal and computational models of development of graded vowel
categories.

Some acoustic instances of phonetic segments are phonemically more
compelling than others, and studies involving human infants and monkeys suggest
that experience plays a critical role in modifying the manner in which subjects
respond to between and within phonetic category differences. In this study,
eight European starlings (Sturnus vulgaris) were trained to discriminate vowel
tokens drawn from stylized distributions either of the Engish vowel categories
/i/ and /I/, or of the Swedish vowel categories /y/ and /(barred you)/.
Following training, responses to novel stimuli drawn from these distributions
indicated that starlings' responses generalized with facility to novel category
examples. Multiple linear regression analyses revealed that responses could be
well predicted on the bases of F1 and F2 values and distributional
characteristics of experienced vowel sounds. Responses manifested a graded
structure about the central ``prototypical'' vowel of the training category.
Starling response rates (/i-I/birds) corresponded closely to adult human
judgments of ``goodness'' for the English vowel sounds. Finally, a simple linear
association network model trained with vowels drawn from the training set
captured 95% of the variance in birds' response rates for novel vowel tokens.
[Work supported by NIDCD and NSF.]